Nova Companys total overhead cost at various levels of activity are presented below:

Month	Machine- Hours		Total Overhead Cost
April	50,000		$	191,500
May	40,000		$	169,600
June	60,000		$	213,400
July	70,000		$	235,300

Assume that the total overhead cost above consists of utilities, supervisory salaries, and maintenance. The breakdown of these costs at the 40,000 machine-hour level of activity is:

Utilities (variable)	$	44,000
Supervisory salaries (fixed)		63,000
Maintenance (mixed)		62,600
Total overhead cost	$	169,600

Nova Companys management wants to break down the maintenance cost into its variable and fixed cost elements.

Required:

1. Estimate how much of the $235,300 of overhead cost in July was maintenance cost. (Hint: To do this, it may be helpful to first determine how much of the $235,300 consisted of utilities and supervisory salaries. Think about the behavior of variable and fixed costs!) (Do not round intermediate calculations.)

2. Using the high-low method, estimate a cost formula for maintenance. (Do not round your intermediate calculations. Round the "Variable cost per machine-hours" to 2 decimal places.)

3. Express the companys total overhead cost in the linear equation form Y = a + bX. (Do not round your intermediate calculations. Round the "Variable cost per machine-hours" to 2 decimal places.)

4. What total overhead cost would you expect to be incurred at an activity level of 45,000 machine-hours? (Do not round intermediate calculations.)